Azaserine is a carcinogen

Carcinogen

A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

 primarily used for researching pancreatic cancer in animal models. It is a glutamine

Glutamine

Glutamine is one of the 20 amino acids encoded by the standard genetic code. It is not recognized as an essential amino acid but may become conditionally essential in certain situations, including intensive athletic training or certain gastrointestinal disorders...

 analogue that irreversibly inhibits glutamine utilizing enzymes such as Gln: Phosphoribosyl Amidotransferase

Amidophosphoribosyltransferase

Amidophosphoribosyltransferase , also known as glutamine phosphoribosylpyrophosphate amidotransferase , is an enzyme that in humans is encoded by the PPAT gene.- Function :...

, which is involved in the biosynthesis of Inosine monophosphate (IMP). IMP is an important precursor to the purine

Purine

A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....

 nucleotide

Nucleotide

Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...

s which include Adenosine monophosphate

Adenosine monophosphate

Adenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...

 (AMP) and Guanosine monophosphate

Guanosine monophosphate

Guanosine monophosphate, also known as 5'-guanidylic acid or guanylic acid and abbreviated GMP, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside guanosine. GMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase...

 (GMP).

Further enzymes of purine and pyrimidine metabolism are inhibited as well. Therefore it was tested as anti-cancer drug by different authors in different indications (not only pancreatic cancer) in pre-clinical settings. Further glutamine analogues that were tested as anti-cancer drugs are DON

6-Diazo-5-oxo-L-norleucine

6-Diazo-5-oxo-L-norleucine is a glutamine antagonist, which was isolated originally from Streptomyces. It is a non-standard amino acid. The diazo compound was characterized in 1956 by Henry W Dion et al., who suggested a possible use in cancer therapy. This antitumoral efficacy was confirmed in...

 and Acivicin

Acivicin

Acivicin is a glutamine analog antimetabolite, used as an antineoplasitc agent. It is fermented product of Streptomyces sviceus. It interferes with glutamate metabolism and inhibits glutamate dependent synthesis of enzymes, and is thereby potentially helpful in the treatment of solid...

.